Further research and testing of cementitious coatings as described in U.S. Pat. No. 4,088,804 revealed several problems that were not known at the time of the above patent application. There was not adequate corrosion resistance and many of the finely divided minerals were not suitable for a good coating. It was further found that sodium nitrite and calcium nitrite were not a corrosion inhibitor, in fact, calcium nitrite increased the corrosion of steel. A new approach was then taken to correct these deficiencies as later described. It was further found that calcium stearate did not add to water impermeability. Also, glycol and glycerine were of no value in adding to the corrosion resistance of the coating.
The new environmental restrictions have imposed restrictions on air pollution which have caused major changes in the paint industry. This coating meets or exceeds all Federal and State requirements for paints and coatings.